Binding studies of platelet alpha 2- and lymphocyte beta 2-adrenoceptors in patients with cirrhosis.

Radioligand binding studies were performed on 10 patients with cirrhosis and 10 healthy subjects. Bmax and KD of platelet alpha 2-adrenoceptors, studied using [3H]-yohimbine, were similar in both groups (Bmax 24.9 vs 22.1 fmol/10(9) platelets, P = 0.47; KD 4.6 vs 5.5 nmol 1-1, P = 0.56). Bmax and KD of lymphocyte beta 2-adrenoceptors, studied using [125I]-iodocyanopindolol, were also similar in both groups (Bmax 24.0 vs 27.2 fmol mg-1 protein, P = 0.55; KD 49.6 vs 55.3 pmol 1-1, P = 0.65). In this model there is no evidence of adrenoceptor down-regulation in cirrhosis despite the increased sympathetic activity in this condition.